Say Goodbye To Traditional Transplants: The Superiority Of DALK In Treating Keratoconus

(Posted on Wednesday, February 7, 2024)

This story is part of a series on the current progression in Regenerative Medicine. This piece is part of a series dedicated to the eye and improvements in restoring vision. 

In 1999, I defined regenerative medicine as the collection of interventions that restore tissues and organs damaged by disease, injured by trauma, or worn by time to normal function. I include a full spectrum of chemical, gene, and protein-based medicines, cell-based therapies, and biomechanical interventions that achieve that goal.

The human eye is an incomparable work of art, a marvel of evolution that enables us to experience the delightful range of colors, shapes, and textures of the world around us. Unfortunately, millions of people worldwide struggle with corneal diseases that significantly impair their vision and quality of life. Until recently, traditional full-thickness corneal transplants were the cornerstone of treatment for such patients, but they had some drawbacks, notably a higher risk of rejection and complications.

Enter Deep Anterior Lamellar Keratoplasty (DALK), which is a cutting-edge, targeted approach to corneal transplantation that revolutionizes how ophthalmologists treat keratoconus and other corneal conditions. DALK is a regularly performed eye surgery that addresses damage to the outermost layers of the cornea, leaving the essential, healthy innermost layer untouched. This selective approach slashes the risk of rejection and other complications, making it an exciting and attractive option for people with corneal disorders.

What is DALK?

DALK is an advanced surgical technique that selectively replaces only the front 95% of the cornea with donor tissue while preserving the thin back layers of the patient’s cornea. This procedure is typically performed on patients with corneal scars or other abnormalities affecting the front of the cornea. 

During the DALK procedure, the surgeon removes the outer layer (epithelium) and the abnormal front layers of the cornea, leaving the healthy back layers intact. The donor tissue is then carefully placed onto the remaining back layers of the patient’s cornea and secured with sutures. 

By preserving the delicate pump cell layer lining the back of the cornea (the corneal endothelium) and the thin back layers, DALK reduces the risk of complications while improving the patient’s vision. The corneal endothelium is critical in maintaining corneal transparency and preventing swelling. 

Compared to traditional full-thickness corneal transplants, which require the removal of the entire cornea, DALK only replaces the affected layers. This approach minimizes the risk of rejection by the patient’s immune system, reduces healing time, and enables patients to return to their daily routines more quickly. 

The Effectiveness of DALK

Several studies have explored the efficacy of Deep Anterior Lamellar Keratoplasty (DALK) as a treatment option for patients with keratoconus. This technique has a success rate of almost 90% in improving visual acuity among keratoconus patients.

Comparative studies between DALK and traditional full-thickness corneal transplants further support DALK as a better option for keratoconus patients. Moorfields Eye Hospital’s publication in Eye indicates that DALK patients experience faster healing times, better visual acuity, and fewer complications than those who undergo traditional transplants. This sentiment is echoed by another study that suggests that DALK has become an effective treatment for keratoconus.

Long-term studies also point to the increasing use of DALK and other types of lamellar keratoplasty in treating the condition. Another study cited in Therapeutic Advances in Ophthalmology found that the graft rejection rate in patients receiving selective replacement was only 9%, denoting a high success rate. Furthermore, a 10-year review also cited in Therapeutic Advances in Ophthalmology suggests a significant increase in DALK usage and a decrease in traditional full-thickness corneal transplant methods.

Wrapping it Up

Selective replacement of the diseased corneal layer is a newer treatment option that only replaces the diseased portion of the cornea while preserving the healthy pump cell layer. This technique has shown great promise for patients with keratoconus as it reduces the risk of complications and improves visual acuity. Additionally, patients who undergo DALK can return to their daily routines more quickly than with traditional corneal transplantation.

Although more research is needed to fully understand DALK’s effectiveness, current clinical trials and outcomes are encouraging. With continued advancements in surgical techniques and technology, the future of corneal transplantation looks bright. Patients with keratoconus can hope for a safer and more effective treatment option with DALK.

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